Conditioning shampoos or “2 in 1” hair products comprising a detersive surfactant and hair conditioning agents are known. These personal care compositions typically comprise an anionic detersive surfactant in combination with a conditioning agent such as a silicone, hydrocarbon oil, fatty esters, etc. These products have become more popular among consumers as a means of conveniently obtaining hair conditioning and cleansing performance from a single product.
Many conditioning personal care compositions, however, do not provide sufficient deposition of conditioning agents onto hair or skin during the application process and if deposition is possible, it is only possible in formulations with relatively low levels of anionic surfactant. Without adequate deposition, large proportions of conditioning agent are rinsed away during the application process and therefore provide little or no conditioning benefit. Without sufficient deposition of the conditioning agent on the hair or skin, relatively high levels of conditioning agents may be needed. Such high levels of a conditioning agent, however, can increase raw material costs, reduce lathering, and present product stability concerns. Additionally, limitations on total anionic surfactant in order to form coacervate can limit the lather potential of a composition, or result in the need for higher levels of less cost effective amphoteric surfactants in order to achieve good lather.
One known method for improving deposition of a hair conditioning agent onto hair involves the use of specific cationic deposition polymers. These polymers may be synthetic, but are most commonly natural cellulosic or guar polymers that have been modified with cationic substituents.
The formation of a coacervate upon dilution of the cleansing composition with water is important to improving deposition of various conditioning actives, especially those that have small droplet sizes (i.e., ≦2 microns). In order to form a coacervate, cleansing compositions comprising typical cationic polymers tend to be significantly limited in total anionic surfactant concentrations, in order to achieve adequate levels of coacervate particles upon dilution. However, lower levels of anionic surfactants tend to limit the volume of lather that can be achieved with a particular cleansing composition. Thus, for cost effective, high lathering, coacervate-forming compositions, it is desirable to use a cationic polymer that can form a coacervate in the presence of high levels of anionic surfactant.
But another complexity arises when the composition comprises an active substance, such as an anti-dandruff active, which also needs to be deposited on the scalp in an efficacious deposition amount and quality. However, excellent deposition amount and quality of active substances, for example by utilizing high levels of cationic polymers and those with higher charge density, is often associated with a hair conditioning feel that many consumers find unacceptable.
Consequently, needs exist for a conditioning composition that provides excellent active substance deposition performance without a hair conditioning and hair feel trade-off.